diff --git a/apps/sunclock/README.md b/apps/sunclock/README.md
index 622a11ba3..4076767d9 100644
--- a/apps/sunclock/README.md
+++ b/apps/sunclock/README.md
@@ -1,5 +1,5 @@
 # Sun Clock
-Clock showing date/time, sunset/sunrise, sun height/azimuth
+Clock showing date/time, sunset/sunrise, H = current sun height/noon sun height, Az = sun azimuth
 
 ![](screenshot_sunclock.png)